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>Chapter 36. Triggers</H1
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>Table of Contents</B
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><DT
>36.1. <A
HREF="trigger-definition.html"
>Overview of Trigger Behavior</A
></DT
><DT
>36.2. <A
HREF="trigger-datachanges.html"
>Visibility of Data Changes</A
></DT
><DT
>36.3. <A
HREF="trigger-interface.html"
>Writing Trigger Functions in C</A
></DT
><DT
>36.4. <A
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>A Complete Trigger Example</A
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>   This chapter provides general information about writing trigger functions.
   Trigger functions can be written in most of the available procedural
   languages, including
   <SPAN
CLASS="APPLICATION"
>PL/pgSQL</SPAN
> (<A
HREF="plpgsql.html"
>Chapter 39</A
>),
   <SPAN
CLASS="APPLICATION"
>PL/Tcl</SPAN
> (<A
HREF="pltcl.html"
>Chapter 40</A
>),
   <SPAN
CLASS="APPLICATION"
>PL/Perl</SPAN
> (<A
HREF="plperl.html"
>Chapter 41</A
>), and
   <SPAN
CLASS="APPLICATION"
>PL/Python</SPAN
> (<A
HREF="plpython.html"
>Chapter 42</A
>).
   After reading this chapter, you should consult the chapter for
   your favorite procedural language to find out the language-specific
   details of writing a trigger in it.
  </P
><P
>   It is also possible to write a trigger function in C, although
   most people find it easier to use one of the procedural languages.
   It is not currently possible to write a trigger function in the
   plain SQL function language.
  </P
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